WR450 2004 overheat ,jetting?

Hello guys

I’m new on the forum, I have read a lot in here and find many useful info, however I’m still lost with my bike.

I have some experience with bikes but never this kind of 4stroke.

I bought a wr450 from a deceased guy I notice the bike has been modified (full exhaust ron wood, high flow filter, spark iridium BR8EIX, funny rear suspension and who knows what else) when I bought it, the bike have been sitting for almost 2 years.

I open the carb it had a lot of dry gas, I clean it change the pilot jet for a new one and put a sunlight air mixture screw .

Also change the front suspension seals (thank you guys for the info about that)

I read in here that a normal setting for a wr450 will be something like:

Pilot 45 or 48

Main 165 or 168

Clip around 4 position

Slow 65 or 68

But what I got is totally different

Pilot 50

Main (it doesn’t said) but I compared to a 178 and seems even bigger

Clip 3 position (from bottom)

Slow 65

(I ride in Quebec Canada, if it is of any use that info)

The bike runs more or less ok, but start with choke in really high revolutions, when I ride slow in a wooded area it overheats really bad, now I don’t know if it is normal or the jetting has something to do with this.

Some times before a turn, with the clutch press the bikes turn off in low rev., of course when I release it start again.

I have no big complains because for the price it starts and runs, good enough for me, but I’m afraid I will kill the engine if it overheats too much, (like a 2 stroke)

I suspect they play around with the timing (new cam or something) because goes really fast to high rev. But I have no way of knowing (His family doesn’t know).

Of course I can take it to a shop and ask them to fix everything even change the exhaust that I hate (too much noise, I don’t need the power) but I’m trying to spend as little as I can because this is just a hobby for me.

Hope I put enough and the right info, thank you for any tips that you can have about this

Edited by Where-to-ride

How slow are you going when it overheats? Mine does the same if I'm clutching and revving a lot in the slow stuff.

There's a jetting database on here which shows What's best for your elevation as well.

For the exhaust if you hate it see if someone will trade for their stock exhaust!

As for turning off in low revs find the screw by the carb that controls this and turn clockwise till it stops dying on you

Edited by Stealth13

Ok is good to know that the overheat is normal in some occasions, now that you mention it, the place where I ride is kind of difficult for my level so I go slow and clutching a lot, probably the problem is me and not the bike :thumbsup:

I check the database from here and I found useful stuff but I haven’t have much luck in fixing my problem, I guess I will keep at it, reading info and testing until is fixed.

Good point, I’ll put the exhaust at kijiji before summer goes.

(Do you know any Canadian store on the web that sales parts and this kind of things and ship to Quebec?)

about the carb. screw, I let you know what happen next ride.


Ps. If there is anyone from Quebec around, in particular the st. jean area, where you ride? Trails, no track, I found that around here the VTT are really popular but the dirt bike are not much welcome.

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